This invention relates generally to means for pivotally joining a flight control element to a corresponding airfoil in a model airplane of fixed wing type and, more specifically to the pivotal joinder of the element to the airfoil by means of a plurality of flexible string hinges.
Broadly speaking, it has a long been known in the model airplane prior art to pivotally join flight control elements, such as ailerons, rudders and elevators, to their corresponding airfoils such as wings, vertical stabilizer fins and horizontal stabilizer members, respectively. One such prior art joinder means is a plurality of spaced apart flexible plastic hinge strips used to pivotally join an aileron to a wing in a model airplane as disclosed in U.S. Pat. No. 3,645,481 granted to L. R. Purdy on Feb. 29, 1972. Such flexible hinge strips are sometimes referred to as xe2x80x9clivexe2x80x9d hinges. In addition, hinges having a pair of plastic flaps joined together by a hinge pin have also been used in the prior art. Further, strips of flexible flat fabric have been used as hinges to adjoin model airplane airfoils to flight control surfaces. These hinges are inserted in elongated slots that oppose one another which are formed in a trailing edge of an airfoil and in a leading edge of a corresponding control element.
A problem that has been encountered using the previously mentioned prior art hinges is the difficulty in closely aligning pairs of opposing slots formed in a trailing edge of an airfoil and in an adjacent leading edge of a corresponding control element for insertion of the flat plastic or fabric hinge therein. If the opposing slot pairs are not closely aligned, the hinge either will not fit or, if forced to fit, will contain a bend or wrinkle therein which over time, can weaken the hinge joint to the point of breakage or failure or can adversely affect the range of motion of the control element relative to the corresponding airfoil or both. Also, if the opposing slots are not properly aligned, binding of a plastic hinge can occur which can severely affect the flight path of a model airplane even to the point of causing a crash.
By means of our invention, these and other difficulties encountered using conventional prior art hinge structure to join a model airplane airfoil to a corresponding flight control element are substantially overcome. The string hinges of my invention are easier to install, can not produce binding, are easier to align across the gap between an airfoil and its control member and are less prone to failure than is the case with conventional plastic or fabric hinges.
It is an object of our invention to provide a novel means for pivotally joining an airfoil to a flight control member in a model airplane.
Briefly, in accordance with our invention, there is provided, in a model airplane structure, means for pivotally connecting at least one flight control member to a corresponding airfoil. The means comprises a series of spaced apart, flexible string members tightly strung between the flight control member and the corresponding airfoil.